That wouldn't be the Ballybriggan market would it? Popped in there on my way down from Belfast a few weeks ago, was approached quietly by this big lad asking if we were interested in a laptop. It was all very suss!
That and the 4 DVDs for €10 tables...
I got a Sony MZ-RH900 (or something like that) for €300, needed the microphone port which meant getting one of the more expensive ones. It's not quite top of the range but has everything I'll probably ever need in a MD recorder.
For only 40 quid less you get no warranty, no guarantee where it came from... may not even be working! I'd go with the new one. Check online shops & ebay and the likes, I'd say you'd probably do at least as well.